Here are some spoiler-free quotes from it that I found interesting.

Geralt doesn’t say much, doesn’t do stupid things. He’s a badass, and a measured one. He’s Clint fucking Eastwood. But that also means he isn’t the kind of person you’d go to a party with. He doesn’t let his hair down, doesn’t like to share his feelings. Doesn’t get drunk, doesn’t put innocents in peril or steal from them. He hates formality and wealth: his home is the road. This attitude very much informs the nature of what he does in The Witcher 3.

And that made it very hard for CD Projekt to find a solid narrative foundation for Hearts of Stone. “We wanted to tell a story that put the players in different situations to the main game, wanted it to be very different,” lead quest designer Mateusz Tomaszkiewicz tells me. But with it came the struggle to justify why Geralt would participate in these different kinds of quests as the team began planning Hearts of Stone, three months before the launch of The Witcher 3.

The answer lay in Pan Twardowski, a Polish folk story. It’s about a sorcerer who signs a pact with the devil but then wriggles out of it by including a clause that prevents the devil from completing his side of it. CD Projekt had written a quest inspired by the story, which became a chain of quests, which then mutated into the spine of Hearts of Stone: with Geralt having made a deal that he can’t back out of, he’s forced to do things he’d never normally do.

The brand on Geralt's face serves to make the quest feel urgent. “It reminds you’re somehow in debt,” says Tomaszkiewicz. He was concerned that Hearts of Stone’s quests needed to both capture players, giving them a strong incentive to play it, and also ensure it felt grounded in the main narrative. The brand is always visible, no matter how distracted you get in other things.

“We thought it’d be a good idea if you would have some personal grudge against the quest giver, Olgierd,” says Tomaszkiewicz. But he’s simply too interesting and charismatic for that to fully work. “I think it wasn’t as much of a motivation for people as we hoped,” Tomaszkiewicz says, having taken in the opinions in reviews and comments.

So how do you solve a problem like Geralt? Hearts of Stone’s answer is to make him an offer he can’t resist and a price he can’t afford. The result is quite different to anything you play in the main game, and yet the same rich and humanistic heart still beats under it all, and at its end, the world and Geralt himself seem even more vivid.